Extracts on an Ex Vivo Experimental Model of Ulcerative Colitis

Oral aged garlic (Allium sativum) alleviates ulcerative colitis in mice by improving gut homeostasis

Aged garlic, obtained by heating raw garlic (Allium sativum) under high temperature and controlled humidity for a period, possesses a wide range of bioactivities, but its role in ulcerative colitis and its mechanism are not fully elucidated. We investigated the bioactive constituents in aged garlic (AG) and explored the effect of oral AG delivery on DSS-induced murine colitis. The results revealed that the aging process up-regulated anti-oxidative, anti-inflammatory and anti-microbial compounds such as dihydrocaffeic acid, 5-acetylsalicylic acid, verticine, S-allyl-L-cysteine and D-fucose. Oral AG obviously alleviated colitis, reducing colon damage and enhancing anti-oxidative and anti-inflammatory effects. Escherichia coli and Streptococcus equinus dramatically were enriched in the colon of mice with colitis that were strongly associated with Parkinson's disease, bacterial invasion of epithelial cells, aerobactin biosynthesis, and heme biosynthesis, but a distinct AG-mediated alteration in the colon due to increasing abundance of Akkermansia muciniphila, Lactobacillus sp. L-YJ, Bifidobacterium breve, Blautia wexlerae, Desulfomicrobium sp. P100A, and Lentilactobacillus hilgardii was observed. Next, we demonstrated that colonic microbiome reconstruction by oral AG significantly increased the production of short-chain fatty acids such as acetic acid, propionic acid, isobutyric acid, and isovaleric acid. This study provides the first data indicating that oral AG ameliorates colonic inflammation in a gut microbiota-dependent manner. Our findings provide novel insights into the AG-mediated remission of colitis and AG as a functional food for modulating the gut microbiota to prevent and treat colitis.

Natural approaches for the management of ulcerative colitis: evidence of preclinical and clinical investigations

Ulcerative colitis (UC) is a recurring autoimmune disorder characterized by persistent inflammation in the mucosal lining of the lower part of the large intestine. Conventional treatment options such as salicylates, corticosteroids, and immunosuppressants often come with severe side effects, limited bioavailability, and the development of drug resistance, which hampers their therapeutic effectiveness. Therefore, it is imperative to explore natural strategies as safe and alternative treatments for UC. Currently, around 40% of UC patients find relief through natural constituents, which can help reduce toxic side effects and maintain clinical remission. This review aims to provide a summary of both preclinical and clinical evidence supporting the efficacy of various natural substances in the prophylaxis of UC. These natural options include plant extracts, essential oils, nutraceuticals, and phytochemicals. Furthermore, we will delve into the potential mechanisms that underlie the protective and curative actions of these novel herbal agents. In summary, this review will explore the effectiveness of natural remedies for UC, shedding light on their preclinical and clinical findings and the mechanisms behind their therapeutic actions. These alternatives offer hope for improved treatment outcomes and reduced side effects for individuals suffering from this challenging autoimmune condition.

Anti-inflammatory and anti-hyperalgesic effects induced by an aqueous aged black garlic extract in rodent models of ulcerative colitis and colitis-associated visceral pain

Inflammatory bowel disease (IBD) is a morbid condition characterized by relapsing-remitting inflammation of the colon, accompanied by persistent gut dysmotility and abdominal pain. Different reports demonstrated biological activities of aged black garlic (ABG), including anti-inflammatory and antioxidant effects. We aimed to investigate beneficial effects exerted by ABGE on colon inflammation by using ex vivo and in vivo experimental models. We investigated the anti-inflammatory effects of an ABG water extract (ABGE) on rat colon specimens exposed to E. coli lipopolysaccharide (LPS), a known ex vivo experimental model of ulcerative colitis. We determined gene expression of various biomarkers involved in inflammation, including interleukin (IL)-1β, IL-6, nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α. Moreover, we studied the acute effects of ABGE on visceral pain associated with colitis induced by 2,4-di-nitrobenzene sulfonic acid (DNBS) injection in rats. ABGE suppressed LPS-induced gene expression of IL-1β, IL-6, NF-kB, and TNF-α. In addition, the acute administration of ABGE (0.03-1 g kg-1) dose-dependently relieved post-inflammatory visceral pain, with the higher dose (1 g kg-1) able to significantly reduce both the behavioral nociceptive response and the entity of abdominal contraction (assessed by electromyography) in response to colorectal distension after the acute administration in DNBS-treated rats. Present findings showed that ABGE could represent a potential strategy for treatment of colitis-associated inflammatory process and visceral pain. The beneficial effects induced by the extract could be related to the pattern of polyphenolic composition, with particular regard to gallic acid and catechin.

Huaier Polysaccharide Alleviates Dextran Sulphate Sodium Salt-Induced Colitis by Inhibiting Inflammation and Oxidative Stress, Maintaining the Intestinal Barrier, and Modulating Gut Microbiota

The incidence of ulcerative colitis (UC) is increasing annually, and UC has a serious impact on patients' lives. Polysaccharides have gained attention as potential drug candidates for treating ulcerative colitis (UC) in recent years. Huaier (Trametes robiniophila Murr) is a fungus that has been used clinically for more than 1000 years, and its bioactive polysaccharide components have been reported to possess immunomodulatory effects, antitumour potential, and renoprotective effects. In this study, we aimed to examine the protective effects and mechanisms of Huaier polysaccharide (HP) against UC. Based on the H2O2-induced oxidative stress model in HT-29 cells and the dextran sulphate sodium salt (DSS)-induced UC model, we demonstrated that Huaier polysaccharides significantly alleviated DSS-induced colitis (weight loss, elevated disease activity index (DAI) scores, and colonic shortening). In addition, HP inhibited oxidative stress and inflammation and alleviated DSS-induced intestinal barrier damage. It also significantly promoted the expression of the mucin Muc2. Furthermore, HP reduced the abundance of harmful bacteria Escherichia-Shigella and promoted the abundance of beneficial bacteria Muribaculaceae_unclassified, Anaerotruncus, and Ruminococcaceae_unclassified to regulate the intestinal flora disturbance caused by DSS. Nontargeted metabolomics revealed that HP intervention would modulate metabolism by promoting levels of 3-hydroxybutyric acid, phosphatidylcholine (PC), and phosphatidylethanolamine (PE). These results demonstrated that HP had the ability to mitigate DSS-induced UC by suppressing oxidative stress and inflammation, maintaining the intestinal barrier, and modulating the intestinal flora. These findings will expand our knowledge of how HP functions and offer a theoretical foundation for using HP as a potential prebiotic to prevent UC.

Targeting Metabolic Diseases: The Role of Nutraceuticals in Modulating Oxidative Stress and Inflammation

The escalating prevalence of metabolic and cardiometabolic disorders, often characterized by oxidative stress and chronic inflammation, poses significant health challenges globally. As the traditional therapeutic approaches may sometimes fall short in managing these health conditions, attention is growing toward nutraceuticals worldwide; with compounds being obtained from natural sources with potential therapeutic beneficial effects being shown to potentially support and, in some cases, replace pharmacological treatments, especially for individuals who do not qualify for conventional pharmacological treatments. This review delves into the burgeoning field of nutraceutical-based pharmacological modulation as a promising strategy for attenuating oxidative stress and inflammation in metabolic and cardiometabolic disorders. Drawing from an extensive body of research, the review showcases various nutraceutical agents, such as polyphenols, omega-3 fatty acids, and antioxidants, which exhibit antioxidative and anti-inflammatory properties. All these can be classified as novel nutraceutical-based drugs that are capable of regulating pathways to mitigate oxidative-stress- and inflammation-associated metabolic diseases. By exploring the mechanisms through which nutraceuticals interact with oxidative stress pathways and immune responses, this review highlights their potential to restore redox balance and temper chronic inflammation. Additionally, the challenges and prospects of nutraceutical-based interventions are discussed, encompassing bioavailability enhancement, personalized treatment approaches, and clinical translation. Through a comprehensive analysis of the latest scientific reports, this article underscores the potential of nutraceutical-based pharmacological treatment modulation as a novel avenue to fight oxidative stress and inflammation in the complex landscape of metabolic disorders, particularly accentuating their impact on cardiovascular health.

Oat Peptides Alleviate Dextran Sulfate Sodium Salt-Induced Colitis by Maintaining the Intestinal Barrier and Modulating the Keap1-Nrf2 Axis

The prevalence of inflammatory bowel disease (IBD) is progressively rising each year, emphasizing the significance of implementing rational dietary interventions for disease prevention. Oats, being a staple agricultural product, are abundant in protein content. This study aimed to investigate the protective effects and underlying mechanisms of oat peptides (OPs) in a mouse model of acute colitis induced by dextran sulfate sodium salt (DSS) and a Caco-2 cell model. The findings demonstrated that intervention with OPs effectively mitigated the symptoms associated with DSS-induced colitis. The physicochemical characterization analysis demonstrated that the molecular weight of the OPs was predominantly below 5 kDa, with a predominant composition of 266 peptides. This study provides further evidence of the regulatory impact of OPs on the Keap1-Nrf2 signaling axis and elucidates the potential role of WGVGVRAERDA as the primary bioactive peptide responsible for the functional effects of OPs. Ultimately, the results of this investigation demonstrate that OPs effectively mitigate DSS-induced colitis by preserving the integrity of the intestinal barrier and modulating the Keap1-Nrf2 axis. Consequently, these findings establish a theoretical foundation for the utilization of OPs as dietary supplements to prevent the onset of IBD.

Antihypertensive Effects of an Optimized Aged Garlic Extract in Subjects with Grade I Hypertension and Antihypertensive Drug Therapy: A Randomized, Triple-Blind Controlled Trial

The use of garlic (Allium sativum) for treating arterial hypertension has been recognized as effective for several decades. However, tolerance to treatment is low, and several technological modifications have been developed to improve its tolerability, such as the aging process at controlled temperature and humidity. This study aims to validate the antihypertensive effects of an optimized extract of aged black garlic with low doses of s-allyl-cysteine (SAC) in a Grade I hypertensive population with drug treatment. A randomized, triple-blind, placebo-controlled parallel trial was developed, where a daily supplementation with 0.25 mg/day of SAC for 12 weeks was performed. A reduction in systolic and diastolic blood pressure of 1.8 mmHg (0.7 to 4.1 95% CI) and 1.5 mmHg (0.3 to 3.0 95% CI), respectively, was observed. Similarly, an increase in blood nitric oxide (10.3 µM, 1.1 to 19.5 95% CI) and antioxidant capacity (7 × 10-3 µM TE/min, (1.2 to 13 × 10-3 95% CI) and a reduction in uric acid levels (-0.3 mg/dL, -0.5 to -0.001 95% CI) and ACE activity (-9.3 U/L; -18.4 to -0.4 95% CI) were observed. No changes in endothelial function and inflammatory cytokines were observed. It was concluded that low-dose SAC supplementation in an optimized black-garlic extract allows for an extra-significant reduction in blood pressure in a Grade I hypertensive population receiving drug treatment.

Ginsenoside Rb1 Interfered with Macrophage Activation by Activating PPARγ to Inhibit Insulin Resistance in Obesity

Type 2 diabetes (T2D) is characterized by insulin resistance (IR), often accompanied by inflammation. Macrophage activation acts as an inflammatory response, which is characterized by macrophage recruitment in the initial stage. Ginsenoside Rb1 (Rb1) is a main active ingredient, which is known for its fat-reducing, anti-inflammatory effects. To clarify that Rb1 regulates macrophage activation in adipose tissue and improves tissue inflammation, network pharmacology and molecular docking were used for target prediction and preliminary validation. By constructing the co-culture model of adipose-derived stem cells (ADSC) and primary macrophage (PM), the body adipose tissue microenvironment was simulated to observe the adipogenesis degree of adipocytes under the effect of Rb1. The levels of cytokines, macrophage polarization, and protein or RNA expression in the inflammatory signaling pathway were finally detected. The results showed that 89 common targets of T2D-Rb1 were obtained after their intersection. Furthermore, according to the results of the KEGG pathway and PPI analysis, PTGS2 (COX-2) is the downstream protein of PPARγ-NF-κB. The molecular binding energy of PPARγ-Rb1 is -6.8 kcal/mol. Rb1 significantly inhibited the increase in MCP-1, TNF-α, and IL-1β induced by hypertrophic adipocytes supernatant and promoted the expression of IL-10. Rb1 inhibited the activation of inflammatory macrophages and PM migration and upregulated PPARγ expression with the blocking of NF-κB activation. Additionally, Rb1 promoted the expression of IRS1 and PI3K in the insulin signal pathway, which had a similar effect with ROS. Therefore, Rb1 might affect macrophage activation through PPARγ, which might alleviate obese insulin resistance in T2D early stage.

Anti-Inflammatory, Antioxidant, and WAT/BAT-Conversion Stimulation Induced by Novel PPAR Ligands: Results from Ex Vivo and In Vitro Studies

Activation of peroxisome proliferator-activated receptors (PPARs) not only regulates multiple metabolic pathways, but mediates various biological effects related to inflammation and oxidative stress. We investigated the effects of four new PPAR ligands containing a fibrate scaffold—the PPAR agonists (1a (αEC50 1.0 μM) and 1b (γEC50 0.012 μM)) and antagonists (2a (αIC50 6.5 μM) and 2b (αIC50 0.98 μM, with a weak antagonist activity on γ isoform))—on proinflammatory and oxidative stress biomarkers. The PPAR ligands 1a-b and 2a-b (0.1–10 μM) were tested on isolated liver specimens treated with lipopolysaccharide (LPS), and the levels of lactate dehydrogenase (LDH), prostaglandin (PG) E2, and 8-iso-PGF2α were measured. The effects of these compounds on the gene expression of the adipose tissue markers of browning, PPARα, and PPARγ, in white adipocytes, were evaluated as well. We found a significant reduction in LPS-induced LDH, PGE2, and 8-iso-PGF2α levels after 1a treatment. On the other hand, 1b decreased LPS-induced LDH activity. Compared to the control, 1a stimulated uncoupling protein 1 (UCP1), PR-(PRD1-BF1-RIZ1 homologous) domain containing 16 (PRDM16), deiodinase type II (DIO2), and PPARα and PPARγ gene expression, in 3T3-L1 cells. Similarly, 1b increased UCP1, DIO2, and PPARγ gene expression. 2a-b caused a reduction in the gene expression of UCP1, PRDM16, and DIO2 when tested at 10 μM. In addition, 2a-b significantly decreased PPARα gene expression. A significant reduction in PPARγ gene expression was also found after 2b treatment. The novel PPARα agonist 1a might be a promising lead compound and represents a valuable pharmacological tool for further assessment. The PPARγ agonist 1b could play a minor role in the regulation of inflammatory pathways.